A pulse generator circuit is used in many electronic device application. For example, a pulse generator circuit may be designed to generate a pulse of a predetermined time duration at the rising edge of an input pulse. Alternatively, the circuit may be designed to generate a pulse at the falling edge of an input pulse.
An example of a prior art pulse generator 10 is shown in FIG. 1. An inverting delay circuit 12 has an output which is coupled to one of the inputs of NAND gate 14. The input pulse IN is coupled to the input of the delay circuit 12 and also to the second input of NAND gate 14.
When the input signal IN changes from a low level to a high level (i.e., at a rising edge), the out pulse signal OUT will go from high to low and remain there for the amount of time it takes to propagate the high level IN signal through delay circuit 12 and to node A. When the high signal IN reaches node A (a low level since the circuit 12 is an inverting delay), the output signal OUT will return to a high level. The timing diagram of FIG. 2 illustrates the operation of the prior art circuit.